The Influence of Elastic Support of Component Glass Panes on Deflection and Stress in Insulating Glass Units—Analytical Model

Abstract

Insulating glass units (IGUs) are the most common filling for external building envelopes. These elements have many advantages related to the thermal protection of buildings. However, some climatic loads are generated or modified due to the sealed gas cavity between the glass panes. The gas enclosed in the cavities changes its parameters under external load, which affects the operational deflection and stress in an IGU. In most computational models describing this phenomenon, the component panes are assumed to be simply supported on the edge spacer, which is considered a sufficient approximation. This article, which continues previous work, assumes that the component glass panes can be supported elastically at the edges. The parameter describing this connection is rotational stiffness. Based on the theory of linear–elastic plates, coefficients were determined to calculate the change in cavity volume, deflection, and stress in glass panes. Then, the results of calculations of the influence of rotational stiffness and static values in exemplary IGUs of various structures, loaded with changes in atmospheric pressure and wind, are presented. It was found that a feedback loop occurs here. The deflection and stress in elastically supported single panes are lower than in the case of those simply supported. However, the lower susceptibility to deflection of the component panes weakens the gas interaction in the cavity, and the resultant load on these panes increases. The influence of rotational stiffness on the resulting static values may therefore vary. In the analyzed examples, this influence was primarily negative for symmetrical loads and clearly positive for wind loads.